1. Field of the Invention
The present invention relates to a particle inspection and removal apparatus and a particle inspection and removal program for inspecting a particle adhering onto a surface of a substrate such as a reticle for transferring a circuit pattern onto a semiconductor wafer and removing the particle.
2. Description of the Background Art
As a particle inspection apparatus inspecting a particle on a surface of a substrate, there is known the following particle inspection apparatus as disclosed in Patent document 1. The particle inspection apparatus includes an irradiation optical system irradiating inspection light onto the surface of the substrate, a detection optical system detecting reflected and scattered light by the surface of the substrate, and an information processing device determining whether or not a particle is present on the surface of the substrate based on a light intensity signal obtained by the detection optical system.
Conventionally, if an inspection result of this particle inspection apparatus indicates that a particle is present on the surface of the substrate, the particle is temporarily taken out from within the particle inspection apparatus and removed by user's manual operation using an air gun.
However, when the particle adhering onto the surface of the substrate is removed by user's manual operation, the substrate is possibly damaged. Due to this, it is necessary for an experienced and skilled operator to remove the particle. If the substrate is a reticle with a pellicle, extreme caution is required to remove the particle by manual operation because a pellicle tends to be damaged. Furthermore, since a user determines whether to remove the particle, to confirm whether or not it is necessary to perform a particle removal operation is disadvantageously complicated. Besides, there is a possible determination error depending on the user, and some user possibly overlooks the particle to be removed.
In some cases, not the user but the particle inspection apparatus determines whether or not a particle is present and removes the particle. In this case, the particle inspection apparatus often makes a uniform determination irrespective of types of regions on the substrate.
In a region where a fine circuit pattern is formed, it is necessary to remove even a small particle. In a region where a coarse circuit pattern is formed or where no circuit pattern is formed, it is not always necessary to remove a small particle. In this way, whether to remove a particle or not depends on the region of the surface of the substrate. If the uniform determination is made to detect a particle of a predetermined size uniformly, a removal operation for removing a particle that is not always necessary to remove is performed, disadvantageously resulting in an increase in working time.    Patent document 1: Japanese Unexamined Patent Publication No. 2006-10544    Patent document 2: Japanese Unexamined Patent Publication No. 2006-300705